I was looking for a replacement battery for my N810 and I found an extremely cheap one from Deal Extreme that claims to be the same capacity as the original battery. For $3.25 and free shipping, I couldn't resist trying it out.
I've ordered from Deal Extreme in the past with very good results. They take around 2 weeks to fill and ship the order but if you are not in a hurry, the price is right.
I'm hoping I'm wrong, but I don't think there's anyway in hell that these batteries are nothing more than a cheap chinese knockoff. I guess for that kind of money, it's worth a try, but any battery I've purchased cheap, even when it's stating the same capacity as the original Nokia battery, turns out to be a disappointment. If it turns out that these batteries give you less than 4 hours of use, rather than the the 7 with the nokia genuine battery, I guess you can then decide if those batteries were worth it to you. If they give you the full genuine Nokia battery time, then I guess I'll eat crow.
I will post my results. An offhand calculation shows that I can buy 12 of these for the price of the Nokia replacement, unless someone can point me to a good place to get Nokia branded batteries (which are more than likely made in China as well). The best price I found was around $40.
Edit: Ebay seems to have plenty of original batteries for around $15.
If it turns out that these batteries give you less than 4 hours of use, rather than the the 7 with the nokia genuine battery, I guess you can then decide if those batteries were worth it to you. If they give you the full genuine Nokia battery time, then I guess I'll eat crow.
I, too have a cheap knockoff battery (and desk charger!) on the way from eBay, that i paid $6.99 for.
I would be extremely happy if this battery lasts 4 hours. A 4 hour cheap battery means that my OEM battery has just been in the desk charger for 4 hours!
HIGHLY likely that the ones on eBay for $15 are not genuine Nokia. I have an E71, which uses the same BP-4L. I've used a knock-off, it does not last nearly as long as a legitimate one, however for $3, it's a cheap safety-net incase your battery dies and you need to make a phone call.
Having said that, I bought 3, the day that DX started stocking them.
I do have to say that it was significantly cheaper than I could have gotten from Nokia and can give me a bit of use when otherwise I would be stranded. This is assuming I remember to charge it up; it loses charge when not in use much faster than the original...